1. Field of the Invention
The present invention is broadly concerned with an improved synthetic resin (e.g., epoxy) bushing assembly of the type commonly used in dead-front electrical transmission and distribution equipment (e.g., pad-mounted, air-insulated switchgear) and adapted to interconnect with conventional connector elbows. More particularly, it is concerned with such a bushing assembly which is lower in cost as compared with prior designs, and which essentially eliminates stress cracking problems attendant to thermal cycling and molding of the epoxy bushing body about the central metallic conductor rod.
2. Description of the Prior Art
Elongated, skirted bushings have long been used in conjunction with electrical transmission and distribution equipment, for the purpose of providing a convenient means for the connection and disconnection of the equipment within an electrical system. Typically, these bushings are configured to mate with external connector elbows in order to complete an electrical circuit through the associated equipment.
One type of bushing heretofore used includes a central copper rod having a male threaded connection end and an opposed female threaded connection end; an epoxy body is then cast about the rod to form the complete bushing. The central conductive rod can be a 11/4" constant diameter copper or aluminum member, but this necessitates larger skirt diameters and consequently more epoxy. Alternately, the rod ]Ray be machined down to a smaller diameter over a majority of the portion thereof and particularly the region where skirting is applied; or two different diameter sections can be joined to achieve the same end. This lowers the epoxy requirements, but this is at least somewhat offset by the attendant machining or attachment costs.